长链非编码RNA Linc-pint通过调控微RNA-21介导结直肠癌进程的机制研究

Long non-coding RNA Linc-pint mediates the progression of colorectal cancer by regulating miRNA-21

【目的】研究长链非编码RNA Linc-pint在结直肠癌(CRC)中的生物学作用及其分子机制。【方法】通过实时定量聚合酶链反应(qRT-PCR)检测Linc-pint在31对CRC组织及其癌旁正常组织中的表达水平。分析Linc-pint的表达与患者临床病理特征之间的关系;采用Kaplan-Meier生存分析法分析Linc-pint表达与患者预后的关系,Cox回归模型分析各项临床病理特征与患者预后的关系。采用qRT-PCR检测5种常见CRC细胞株中Linc-pint表达水平,通过细胞增殖实验、Transwell侵袭和迁移实验、裸鼠皮下成瘤实验检测Linc-pint对细胞增殖、侵袭及迁移能力的影响。通过qRT-PCR检测Linc-pint的靶基因微RNA(miR)-21在31对CRC组织及其癌旁组织中的表达,并利用皮尔森相关系数分析两者之间的相关性。在CRC细胞中过表达Linc-pint后采用qRT-PCR检测其对miR-21表达的影响。【结果】Linc-pint在癌旁正常组织中表达水平为3.95±1.16,高于CRC组织的2.74±0.95(t=6.17,P<0.05)。Linc-pint高表达CRC患者的总体生存率为62.5%(30/48),高于Linc-pint低表达CRC患者的34.3%(24/70),差异有统计学意义(P<0.05)。过表达Linc-pint后,CRC细胞增殖、侵袭及迁移能力均被抑制(均P<0.05)。在肿瘤组织和癌旁正常组织中,Linc-pint表达水平与miR-21表达水平呈负相关(r=-0.288、-0.908,均P<0.05)。【结论】Linc-pint可通过作用于miR-21介导结直肠癌的增殖、侵袭和迁移。

[Objective]To investigate the biological function and molecular mechanism of long non-coding RNA Linc-pint in colorectal cancer.[Methods]Quantitative real-time quantitative(qRT-PCR)was performed to detect the expression level of Linc-pint in 31 pairs of colorectal cancer tumor and adjacent normal tissues;correlation between the expression level of Linc-pint and the clinicopathological characteristics was analyzed by the chi-square test. Kaplan-Meier survival analysis was used to assess the relationship between Linc-pint expression level and the prognosis of patients. Cox regression model was used to analyze the relationship between clinicopathological characteristics and the prognosis of patients. Expression level of Linc-pint were detected by qRT-PCR in 5 common colorectal cancer cell lines. Effect of Linc-pint on cell proliferation,invasion and migration was measured by cell counting kit-8 assay,Transwell assay and harvested xenografts from nude mice.qRT-PCR was performed to detect the expression level of Linc-pint’s target gene micro RNA(miR)-21 in 31 pairs of colorectal cancer tumor tissues and adjacent normal tissues. Pearson correlation coefficient was used to assess the correlation between Linc-pint and miR-21. qRT-PCR was used to detect the expression of overexpression of Linc-pint on miR-21 in colorectal cancer cells.[Results]Expression level of Linc-pint in normal tissues(3.95±1.16)was significantly higher than that in colorectal cancer tissues(2.74±0.95)(t=6.17,P<0.05). Overall survival rate of patients with high expression of Linc-pint was 62.5%,which was significantly higher than that of patients with low expression of Linc-pint(34.3%,P<0.05). The proliferation,invasion and migration of CRC cells were inhibited after overexpression of Linc-pint. In colorectal cancer tumor and adjacent normal tissues,Linc-pint and miR-21 showed opposite expression in tumor tissues and were negatively correlated(r=-0.288 and-0.908,both P<0.05).[Conclusion]Linc-pint acts as a tumor suppressor by down-regulating the expression level of miR-21 to inhibit the proliferation,invasion and migration of colorectal cancer.